Doubt from alternating current

Can somebody explain why the wattless component of current is i(rms)*sin(phi) and not i(max)*sin(phi)?

Like wattless component of the current is the component that is 90° out of phase with the voltage , so phasor diagram analysis would dictate that its I(max)*sin(phi) ?

Wattless current is componet of current which don't utilise any power.
Why you thinking that Imax should used instead of Irms